Optical disk data erasing apparatus and optical disk data erasing method

ABSTRACT

In an optical disk data erasing apparatus, it is judged whether a loaded optical disk is a write-once optical disk or not, and when the optical disk is a write-once optical disk, disk recording information of the optical disk is obtained according to an instruction from a host computer, and overwriting of the optical disk is performed by irradiating the optical disk with a laser beam having a recording power equal to or higher than that at recording, thereby erasing data recorded on the optical disk. Therefore, the optical disk data erasing apparatus can completely erase the data recorded on the optical disk, easily and inexpensively, without having to use a special apparatus, and without generating substances detrimental to environment.

This application is a divisional application of Ser. No. 09/973,690,filed Oct. 11, 2001.

FIELD OF THE INVENTION

The present invention relates to an apparatus and a method for erasingdata from an optical disk.

BACKGROUND OF THE INVENTION

A CD-R disk is a typical write-once optical disk, and a user can writedata on the CD-R disk only once. However, when the data on the CD-R diskbecomes unnecessary, it is not easy to erase the written data from theCD-R disk. Therefore, the CD-R disk is rendered unplayable by using adisposal method, such as artificially applying a stress to the disk(folding, breaking, or damaging the disk) or changing the mediacharacteristics under high temperature condition, whereby secretinformation recorded on the disk is prevented from leaking.

However, the conventional data erasing method relating to the write-onceoptical disk has the following drawbacks.

1) Reliability is insufficient, that is, it is uncertain whether thedisk is completely unplayable or not.

2) The cost is high.

3) Erasing of data limited to a specific recording area cannot becarried out.

4) Substances detrimental to the environment are released.

It is expected that the CD-R disk market will become widespread in thefuture and, therefore, development of a simple and low-cost method andapparatus for completely erasing recorded data from the CD-R disk hasbeen desired.

SUMMARY OF THE INVENTION

The present invention is made to solve the above-described problems andhas for its object to provide an apparatus and a method for completelyerasing recorded data from write-once optical disks.

Other objects and advantages of the invention will become apparent fromthe detailed description that follows. The detailed description andspecific embodiments described are provided only for illustration sincevarious additions and modifications within the scope of the inventionwill be apparent to those of skill in the art from the detaileddescription.

According to a first aspect of the present invention, there is providedan optical disk data erasing apparatus which is an optical diskrecording apparatus for writing or reading data in/from a recordableoptical disk by irradiating the optical disk with a laser beam, theoptical disk recording apparatus being connected to a host computerthrough an interface bus. The optical disk data erasing apparatuscomprises: a judgement means for judging as to whether a loaded opticaldisk is a write-once optical disk or not; an instruction recognitionmeans for recognizing an instruction from the host computer; and anerasing means for executing a data erasing process on the basis of theinstruction; wherein the erasing means overwrites the optical disk whichis judged as a write-once optical disk by the judgement means, byirradiating the optical disk with a laser beam having the same recordingpower as that at recording, thereby erasing data recorded on the opticaldisk. Therefore, an optical disk data erasing apparatus which is able tocompletely erase data on an optical disk is easily realized at low cost,without having to use a special apparatus, and without generatingsubstances detrimental to environment, whereby leakage of secretinformation can be prevented when the optical disk is discarded.

According to a second aspect of the present invention, there is providedan optical disk data erasing apparatus which is an optical diskrecording apparatus for writing or reading data in/from a recordableoptical disk by irradiating the optical disk with a laser beam, theoptical disk recording apparatus being connected to a host computerthrough an interface bus. The optical disk data erasing apparatuscomprises: a judgement means for making a judgement as to whether aloaded optical disk is a write-once optical disk or not; an instructionrecognition means for recognizing an instruction from the host computer;and an erasing means for executing a data erasing process on the basisof the instruction; wherein the erasing means overwrites the opticaldisk which is judged as a write-once optical disk by the judgementmeans, by irradiating the optical disk with a laser beam having arecording power higher than that at recording, thereby erasing datarecorded on the optical disk. Therefore, an optical disk data erasingapparatus which is able to completely erase data on an optical disk iseasily realized at low cost, without having to use a special apparatus,without generating substances detrimental to environment, wherebyleakage of secret information can be prevented when the optical disk isdiscarded.

According to a third aspect of the present invention, the optical diskdata erasing apparatus according to the first or second aspect furthercomprises a disk recording information acquisition means for acquiringdisk recording information relating to a data-recorded area or adata-unrecorded area of the write-once optical disk, on the basis of adisk recording information acquisition instruction which is issued bythe host computer; wherein the erasing means erases data recorded in thedata-recorded area. Therefore, the data erasing process can be performedon only the data-recorded area, while the data-unrecorded area, whichneeds not be erased, is outside the target of the erasing process,whereby the time required for the erasing process is reduced.

According to a fourth aspect of the present invention, the optical diskdata erasing apparatus according to the third aspect further comprises adetermination means for determining whether data are recorded on thewrite-once optical disk or not, on the basis of the disk recordinginformation which is obtained by the disk recording informationacquisition means; wherein, when data are recorded on the write-onceoptical disk, the erasing means executes the recorded-data erasingprocess; and when no data are recorded on the optical disk, thedetermination means returns an error signal to the host computer tonotify the user that the data erasing process is not going to beexecuted. Therefore, when no data are recorded on the optical disk, theuser can know that there is no need to execute the data erasing processon the disk, whereby the user can perform the erasing process on only adata-recorded optical disk, without performing an unnecessary erasingprocess.

According to a fifth aspect of the present invention, the optical diskdata erasing apparatus according to the third aspect further comprises:a notification means for notifying the user of the disk recordinginformation which is obtained by the disk recording informationacquisition means, through the host computer; and an erasing areadetection means for detecting, when an instruction which specifies adata erasing area is issued from the user through the host computer onthe basis of the disk recording information, an area corresponding tothe specified data erasing area on the basis of the instruction; whereinthe erasing means erases the data recorded in the erasing area which isdetected by the erasing area detection means. Therefore, the user canknow the erasable data area in the loaded optical disk and, as theresult, the user can specify a desired area to be erased.

According to a sixth aspect of the present invention, the optical diskdata erasing apparatus according to the first or second aspect furthercomprises: a setting means with which the user sets, through the hostcomputer, whether the interface bus is to be occupied or not duringexecution of the data erasing process; and a monitor means formonitoring the data erasing state on the basis of a state monitoringinstruction which is periodically issued from the host computer, when itis set that the interface bus is not to be occupied; wherein the hostcomputer is able to execute another process during execution of the dataerasing process, when it is set that the interface bus is not to beoccupied. Therefore, when the user sets that the interface bus is not tobe occupied, the host computer can execute another process while theoptical disk data erasing apparatus executes the data erasing process.Further, when the interface bus is to be occupied, the host computer canspeedily detect the end of the erasing process of the optical disk dataerasing apparatus.

According to a seventh aspect of the present invention, there isprovided an optical disk data erasing apparatus which is an optical diskrecording apparatus for writing or reading data in/from a recordableoptical disk by irradiating the optical disk with a laser beam. Theoptical disk data erasing apparatus comprises: a first jumper switchsetting means for setting ON/OFF of a first jumper switch; a settingidentification means for identifying the setting of the first jumperswitch; a judgement means for making a judgement as to whether a loadedoptical disk is a write-once optical disk or not; an erasing means foroverwriting the write-once optical disk by irradiating the optical diskwith a laser beam having the same recording power as that at recording,according to the setting of the first jumper switch, thereby erasingdata recorded on the optical disk; and an ejection means forautomatically ejecting the optical disk after the data erasing process;wherein, when the first jumper switch is turned ON, the erasing meansstarts the data erasing operation; and when the first jumper switch isOFF or when the judgement means judges that the loaded optical disk isnot a write-once optical disk, the ejection means automatically ejectsthe optical disk, and a display means displays that the data erasingprocess is not to be executed on the optical disk. Therefore, theoptical disk data erasing process can be performed by the optical diskdata erasing apparatus alone, according to an external control, withoutusing the host computer. Further, since the data erasing process isautomated, an optical disk data erasing apparatus capable of erasingrecorded data completely is realized easily, at low cost, wherebyleakage of secret information is prevented when the optical disk isdiscarded.

According to an eighth aspect of the present invention, there isprovided an optical disk data erasing apparatus which is an optical diskrecording apparatus for writing or reading data in/from a recordableoptical disk by irradiating the optical disk with a laser beam. Theoptical disk data erasing apparatus comprises: a first jumper switchsetting means for setting ON/OFF of a first jumper switch; a settingidentification means for identifying the setting of the first jumperswitch; a judgement means for making a judgement as to whether a loadedoptical disk is a write-once optical disk or not; an erasing means foroverwriting the write-once optical disk by irradiating the optical diskwith a laser beam having a recording power higher than that atrecording, according to the setting of the first jumper switch, therebyerasing the data recorded on the optical disk; and an ejection means forautomatically ejecting the optical disk after the data erasing process;wherein, when the first jumper switch is turned ON, the erasing meansstarts the data erasing operation; and when the first jumper switch isOFF or when the judgement means judges that the loaded optical disk isnot a write-once optical disk, the ejection means automatically ejectsthe optical disk, and display means displays that the data erasingprocess is not to be executed on the optical disk. Therefore, theoptical disk data erasing process can be performed by the optical diskdata erasing apparatus alone, according to an external control, withoutusing the host computer. Further, since the data erasing process isautomated, an optical disk data erasing apparatus capable of erasingrecorded data completely is realized easily, at low cost, wherebyleakage of secret information is prevented when the optical disk isdiscarded.

According to a ninth aspect of the present invention, the optical diskdata erasing apparatus according to the seventh or eighth aspect furthercomprises a checking means for checking whether the data erasing processhas normally ended or not; wherein, when the data erasing process forthe write-once optical disk has not normally ended, the ejection meansautomatically ejects the optical disk, and the display means displaysthat the data erasing process had not been executed on the optical disk.Therefore, when the data erasing process has not ended normally, theloaded disk is automatically ejected, and the display means displaysthat the data erasing process has not been executed. Thereby, the useris prevented from recognizing that the erasing process has normallyended, and from discarding the optical disk in which data to be erasedhas not been erased.

According to a tenth aspect of the present invention, the optical diskdata erasing apparatus according to the ninth aspect further comprises asecond jumper switch setting means for setting ON/OFF of a second jumperswitch; wherein the setting identification means identifies the settingof the second jumper switch; when it is identified that the secondjumper switch is ON, the erasing means executes the data erasing processover the entire surface of the optical disk; and when it is identifiedthat the second jumper switch is OFF, the erasing means executes thedata erasing process on a final session. Therefore, the user can selectthe erasing method according to the setting of the second jumper switch,and when there is no need to erase the data over the entire surface ofthe disk, the second jumper switch is turned off to prevent unnecessaryentire-surface erasing from being executed. As the result, the timerequired for the erasing process is reduced, resulting in a low-costoptical disk data erasing apparatus.

According to an eleventh aspect of the present invention, the opticaldisk data erasing apparatus according to the seventh or eighth aspectfurther comprises a disk recording information acquisition means foracquiring information relating to a data-recorded area or adata-unrecorded area of the write-once optical disk; wherein the erasingmeans erases recorded data from the data-recorded area. Therefore, thedata erasing process can be performed on only the data-recorded area,while the data-unrecorded area, which needs not be erased, is outsidethe target of the erasing process, whereby the time required for theerasing process is reduced.

According to a twelfth aspect of the present invention, the optical diskdata erasing apparatus according to the eleventh aspect furthercomprises a determination means for determining. whether data arerecorded on the write-once optical disk or not, on the basis of the diskrecording information obtained by the disk recording informationacquisition means; wherein, when data are recorded on the write-onceoptical disk, the erasing means executes the recorded-data erasingprocess; and when no data are recorded on the write-once optical disk,the ejection means automatically ejects the optical disk, and thedisplay means displays that the data erasing process is not to beexecuted on the optical disk. Therefore, when no data are recorded onthe optical disk, the loaded disk is automatically ejected, and thedisplay means displays that the data erasing process has not beenexecuted, whereby the user knows that there is no need to execute thedata erasing process, and performs the data erasing process on only adata-recorded optical disk, without performing an unnecessary erasingprocess.

According to a thirteenth aspect of the present invention, an opticaldisk data erasing method comprises: a judgement step of making ajudgement as to whether a loaded optical disk is a write-once opticaldisk or not; an instruction recognition step of recognizing aninstruction from a host computer; and a data erasing step of overwritingthe optical disk which is judged as a write-once optical disk in thejudgement step, by irradiating the optical disk with a laser beam havingthe same recording power as that at recording, on the basis of theinstruction, thereby erasing data recorded on the optical disk.Therefore, data on an optical disk can be completely erased easily, atlow cost, without having to use a special apparatus, and withoutgenerating substances detrimental to environment, whereby leakage ofsecret information can be prevented when the optical disk is discarded.

According to a fourteenth aspect of the present invention, an opticaldisk data erasing method comprises: a judgement step of making ajudgement as to whether a loaded optical disk is a write-once opticaldisk or not; an instruction recognition step of recognizing aninstruction from a host computer; and an erasing step of overwriting theoptical disk which is judged as a write-once optical disk in thejudgement step, by irradiating the optical disk with a laser beam havinga recording power higher than that at recording, on the basis of theinstruction, thereby erasing data recorded on the optical disk.Therefore, data on an optical disk can be completely erased easily, atlow cost, without having to use a special apparatus, and withoutgenerating substances detrimental to environment, whereby leakage ofsecret information can be prevented when the optical disk is discarded.

According to a fifteenth aspect of the present invention, the opticaldata erasing method according to the thirteenth or fourteenth aspectfurther comprises: a disk recording information acquisition instructionstep of issuing a disk recording information acquisition instructionfrom the host computer; and a disk recording information acquisitionstep of acquiring information relating to a data-recorded area or adata-unrecorded area of the write-once optical disk, on the basis of thedisk recording information acquisition instruction; wherein datarecorded in the data-recorded area are erased in the erasing step.Therefore, the data erasing process can be performed on only thedata-recorded area, while the data-unrecorded area, which needs not beerased, is outside the target of the erasing process, whereby the timerequired for the erasing process is reduced.

According to a sixteenth aspect of the present invention, the opticaldisk data erasing method according to the fifteenth aspect furthercomprises a determination step of determining whether data are recordedon the write-once optical disk or not, on the basis of the diskrecording information which is obtained in the disk recordinginformation acquisition step; wherein, when data are recorded on thewrite-once optical disk, the recorded data are erased in the erasingstep; and when no data are recorded on the optical disk, an error signalis returned to the host computer in the determination step to notify theuser that the data erasing process has not been executed on the opticaldisk. Therefore, when no data are recorded on the optical disk, the usercan know that there is no need to execute the data erasing process onthe disk, whereby the user can perform the erasing process on only adata-recorded optical disk, without performing an unnecessary erasingprocess.

According to a seventeenth aspect of the present invention, the opticaldisk data erasing method according to the fifteenth aspect furthercomprises: a notification step of notifying the user of the diskrecording information which is obtained in the disk recordinginformation acquisition step, through the host computer; an erasing areaspecification instruction step in which the user issues an instructionfor specifying a data erasing area, on the basis of the disk recordinginformation, through the host computer; and an erasing area detectionstep of detecting, from the data-recorded area obtained in the diskrecording information acquisition step, an area corresponding to thespecified erasing area on the basis of the instruction; wherein datarecorded in the erasing area, which is detected by the erasing areadetection means, are erased in the erasing step. Therefore, the user canknow the erasable data area in the loaded optical disk and, as theresult, the user can specify a desired area to be erased.

According to an eighteenth aspect of the present invention, the opticaldisk data erasing method according to the thirteenth or fourteenthaspect further comprises: a setting step in which the user sets, throughthe host computer, whether an interface bus is to be occupied or notduring execution of the data erasing process; a monitoring instructionstep of periodically issuing an erasing state monitoring instructionfrom the host computer, when it is set that the interface bus is not tobe occupied; and a monitoring step of monitoring the data erasing stateon the basis of the erasing state monitoring instruction. Therefore,when the user sets that the interface bus is not to be occupied, thehost computer can execute another process while the optical disk dataerasing apparatus executes the data erasing process. Further, when theinterface bus is to be occupied, the host computer can speedily detectthe end of the erasing process of the optical disk data erasingapparatus.

According to a nineteenth aspect of the present invention, an opticaldisk data erasing method comprises: a first jumper switch setting stepof setting ON/OFF of a first jumper switch; a setting identificationstep of identifying the setting of the first jumper switch; a judgementstep of making a judgement as to whether a loaded optical disk is awrite-once optical disk or not; an erasing step of overwriting thewrite-once optical disk by irradiating the optical disk with a laserbeam having the same recording power as that at recording, according tothe setting of the first jumper switch, thereby erasing data recorded onthe optical disk; and an ejection step of automatically ejecting theoptical disk after the data erasing process; wherein, when the firstjumper switch is ON, the erasing step starts the data erasing operation;and when the first jumper switch is OFF or when it is judged in thejudgement step that the loaded optical disk is not a write-once opticaldisk, the optical disk is automatically ejected in the ejection step,and it is displayed, in a display step, that the data erasing processhas not been executed on the optical disk. Therefore, the optical diskdata erasing process can be performed by the optical disk data erasingapparatus alone, according to an external control, without using thehost computer. Further, since the data erasing process is automated,recorded data can be completely erased easily, at low cost, wherebyleakage of secret information is prevented when the optical disk isdiscarded.

According to a twentieth aspect of the present invention, an opticaldisk data erasing method comprises: a first jumper switch setting stepof setting ON/OFF of a first jumper switch; a setting identificationstep of identifying the setting of the first jumper switch; a judgementstep of making a judgement as to whether a loaded optical disk is awrite-once optical disk or not; an erasing step of overwriting thewrite-once optical disk by irradiating the optical disk with a laserbeam having a recording power higher than that at recording, accordingto the setting of the first jumper switch, thereby erasing data recordedon the optical disk; and an ejection step of automatically ejecting theoptical disk after the data erasing process; wherein, when the firstjumper switch is ON, the erasing step starts the erasing operation; andwhen the first jumper switch is OFF or when it is judged in thejudgement step that the loaded optical disk is not a write-once opticaldisk, the optical disk is automatically ejected in the ejection step,and it is displayed, in a display step, that the data erasing processhas not been executed on the optical disk. Therefore, the optical diskdata erasing process can be performed by the optical disk data erasingapparatus alone, according to an external control, without using thehost computer. Further, since the data erasing process is automated,recorded data can be completely erased easily, at low cost, wherebyleakage of secret information is prevented when the optical disk isdiscarded.

According to a twenty-first aspect of the present invention, the opticaldisk data erasing method according to the nineteenth or twentieth aspectfurther comprises a checking step of checking whether the data erasingprocess has ended normally or not; wherein, when the data erasingprocess for the write-once optical disk has not ended normally, theoptical disk is automatically ejected in the ejection step, and it isdisplayed, in the display step, that the data erasing process has not tobeen executed on the optical disk. Therefore, when the data erasingprocess has not ended normally, the loaded disk is automaticallyejected, and it is displayed that the data erasing process has not beenexecuted. Thereby, the user is prevented from recognizing that theerasing process has normally ended, and from discarding the optical diskin which data to be erased are not erased.

According to a twenty-second aspect of the present invention, theoptical disk data erasing method according to the twenty-first aspectfurther comprises a second jumper switch setting step of setting ON/OFFof a second jumper switch; wherein the setting of the second jumperswitch is identified in the setting identification step; when it isidentified that the second jumper switch is ON, the data erasing processis executed over the entire surface of the optical disk in the erasingstep; and when it is identified that the second jumper switch is OFF,the data erasing process is executed on a final session in the erasingstep. Therefore, the user can select the erasing method according to thesetting of the second jumper switch, and when there is no need to erasethe data over the entire surface of the disk, the second jumper switchis turned off to prevent unnecessary entire-surface erasing from beingexecuted. As the result, the time required for the erasing process isreduced, resulting in a low-cost optical disk data erasing apparatus.

According to a twenty-third aspect of the present invention, the opticaldisk data erasing method according to the nineteenth or twentieth aspectfurther comprises a disk recording information acquisition step ofacquiring information relating to a data-recorded area or adata-unrecorded area of the write-once optical disk; wherein datarecorded in the data-recorded area are erased in the erasing step.Therefore, the data erasing process can be performed on only thedata-recorded area, while the data-unrecorded area, which needs not beerased, is outside the target of the erasing process, whereby the timerequired for the erasing process is reduced.

According to a twenty-fourth aspect of the present invention, theoptical disk data erasing method according to the twenty-third aspectfurther comprises a determination step of determining whether data arerecorded on the write-once optical disk or not, on the basis of the diskrecording information obtained in the disk recording informationacquisition step; wherein, when data are recorded on the write-onceoptical disk, the recorded data are erased in the erasing step; and whenno data are recorded on the write-once optical disk, the optical disk isautomatically ejected in the ejection step, and it is displayed, in thedisplay step, that the data erasing process has not been executed on theoptical disk. Therefore, when no data are recorded on the optical disk,the loaded disk is automatically ejected, and it is displayed that thedata erasing process has not been executed, whereby the user knows thatthere is no need to execute the data erasing process, and performs thedata erasing process on only a data-recorded optical disk, withoutperforming an unnecessary erasing process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating the construction of a dataerasing apparatus according to the present invention.

FIG. 2 is a block diagram illustrating the construction of a systemaccording to a first or second embodiment of the present invention.

FIGS. 3(a) and 3(b) are a front view and a rear view, respectively, of adata erasing apparatus (drive) according to a third embodiment of thepresent invention.

FIG. 4 is a diagram illustrating an example of a disk format accordingto the present invention.

FIG. 5 is a flowchart illustrating the procedure of a data erasingmethod according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating the procedure of a data erasingmethod according to the second embodiment of the present invention.

FIG. 7 is a flowchart illustrating the procedure of a data erasingmethod according to the third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will bedescribed with reference to the drawings. The embodiments describedhereinafter are merely examples, and the present invention is notrestricted to these embodiments.

Embodiment 1

Hereinafter, an optical disk data erasing apparatus according to a firstembodiment of the present invention will be described. FIG. 1 is adiagram illustrating the construction of an optical disk data erasingapparatus 22.

In FIG. 1, the optical disk data erasing apparatus 22 is an optical diskrecording apparatus for writing or reading data in/from a recordableoptical disk 111 by irradiating the optical disk with a laser beam. Theoptical disk data erasing apparatus 22 comprises a CPU 101, a RAM 102, aROM 103, an EFM encoder/decoder circuit 104, an EFM WOBBLE signalprocessing circuit 105, a laser control circuit 106, a laser pickup 107,a speed change circuit 108, a rotation control circuit 109, and a motor110.

The CPU 101 is provided with an instruction recognition means forrecognizing an instruction from a host computer 21, and controls therespective constituents of the optical disk data erasing apparatus 22according to a command from the ROM 103 or an instruction from the hostcomputer 21. The RAM 102 stores data, and the ROM 103 stores a commandfor controlling the CPU 101. The EFM encoder/decoder circuit 104performs encoding or decoding of various kinds of signals or data. TheEFM WOBBLE signal processing circuit 105 controls a disk drivingmechanism on the basis of WOBBLE information which is read from theoptical disk 111. The disk driving mechanism comprises the motor 110 forrotating the optical disk 111, the speed change circuit 108 for changingthe rotation speed of the motor 110, and the rotation control circuit109 for controlling the rpm (revolutions per minute) of the motor 110.

The laser control circuit 106 performs recording of data into theoptical disk 111 as well as reading of recorded data from the opticaldisk 111, by irradiating the optical disk 111 with a laser beamoutputted from the laser pickup 107 while moving the laser pickup 107from the inner circumference of the rotating optical disk 111 toward theouter circumference. Further, the laser control circuit 106 is providedwith an erasing means for executing a data erasing process on the basisof an instruction from the host computer, whereby recorded data on theoptical disk 111 is erased.

The optical disk data erasing apparatus 22 constructed as describedabove is provided with a judgement means for making a judgement as towhether the loaded optical disk 111 is a write-once optical disk (CD-Rdisk) or not; a disk recording information acquisition means foracquiring information relating to a data-recorded area or adata-unrecorded area of the CD-R disk 111 on the basis of a diskrecording information acquisition instruction from the host computer 21;a notification means for notifying the user that the disk recordinginformation is obtained, through the host computer 21; an erasing areadetection means for detecting, when an instruction that specifies anarea from which data are to be erased (hereinafter referred to as a dataerasing area) is issued by the user through the host computer 21 on thebasis of the disk recording information, an area corresponding to thespecified data erasing area; and a determination means for determiningwhether data are recorded on the CD-R disk 111 or not, on the basis ofthe disk recording information.

The erasing means overwrites the optical disk 111 which is judged as aCD-R disk by the judgement means, by irradiating the optical disk 111with a laser beam having a recording power equal to or higher than thatat recording, thereby erasing the data recorded on the optical disk 111.

FIG. 2 is a block diagram illustrating the construction of an opticaldisk data erasing system according to the present invention.

In FIG. 2, the optical disk data erasing apparatus 22 and the hostcomputer 21 are connected through an interface cable 23, and variouskinds of commands are outputted from “Writing Software” that is arecording application in the host computer 21 to the data erasingapparatus 22.

FIG. 4 is a diagram illustrating an example of a disk format.

In FIG. 4, 41 denotes a PCA (Power Calibration Area) for obtaining anaccurate recording power of a disk. 42 denotes a PMA (Program MemoryArea) wherein information about the start time or end time of analready-recorded track or a reserved track, information for identifyingthe disk, and the like are stored. One session is composed of a read-inarea 43, a program area 44, and a read-out area 45, and a plurality ofsessions are recorded in a single disk. Recording should be carried outso that the sessions are sequentially recorded from the innercircumference of the disk toward the outer circumference.

In each session, the read-in area 43 indicates the position where dataare recorded, and holds a TOC (Table of Contents) which is trackinformation of the session. The program area 44 holds informationincluding user data and a pass table from the immediately precedingsession. The read-out area 45 indicates the end of data.

It is assumed that a session 1 and a session 2 are already closed whilea session 3 is in the open state, and tracks 1˜3 are recorded in therespective sessions 1˜3.

When the host computer 21 outputs an instruction for erasing the entiresurface of the disk, the data erasing apparatus 22 overwrites anoverwrite target area 1 to erase data from the area 1. When the hostcomputer 21 outputs an instruction for erasing only the session 3 whileleaving the sessions 1 and 2 as effective data, the data erasingapparatus 22 overwrites an overwrite target area 2 to erase data fromthe area 2.

Next, a description will be given of a method for reading data recordedon the disk.

In the case where the disk is loaded to obtain all of track informationand latest user data information (i.e., a pass table recorded in thefinal session), the information in the read-in area 43 at the innermostcircumference is read out, and when it is judged that the loaded disk isa multi-session-recorded disk, the disk is searched for all of trackinformation up to the final session and the pass table in the finalsession.

As a method of searching the disk for all of track information up to thefinal session, there is a method of sequentially reading the read-inareas of the respective sessions. In this method, initially, the TOCinformation in the read-in area 43 of the session 1 is read, and theread-in area 43 of the session 2 is accessed on the basis of theobtained program start time of the session 2 to read the TOC informationof the session 2 and, thereafter, the read-in area 43 of the session 3is accessed on the basis of the obtained program start time of thesession 3. Since there is no data in the read-in area 43 of the session3, this area is judged as an unrecorded area, and the previous session 2is judged as the final session. When all of track information up to thefinal session is obtained, access is made to, for example, the passtable of the final session on the basis of the track information of thefinal session, thereby obtaining the pass table of the final session orthe like.

Next, an optical disk data erasing method according to the firstembodiment will be described with reference to FIG. 5.

When the optical disk 111 is loaded on the data erasing apparatus 22,initially, the CPU 101 controls the rotation control circuit 109 to spinup the motor 110 in step S51. Then, the loaded optical disk 111 isirradiated with a laser beam to read data recorded on the optical disk111, and it is checked whether the optical disk 111 is a CD-R disk ornot, on the basis of WOBBLE information which is obtained through theEFM WOBBLE signal processing circuit 105, followed by step S52.

In step S52, it is checked whether or not the data erasing apparatus 22receives a disk recording information acquisition command (a command of“Read Disk Information” or “Read Track Information”) which is issuedfrom the host computer 21. When the apparatus 22 receives this command,the process goes to step S53.

The disk recording information is obtained as follows. The outline ofthe disk recording state is grasped on the basis of the informationabout the start time and end time of the already-recorded track andreserved track, which information is recorded in the PMA 42 at the innercircumference of the disk 111, and the TOC information which is recordedin the read-in area 43 of each session, and a break of pits between thedata-recorded area and the data-unrecorded area is actually detected toobtain the details of the disk recording state, whereby the diskrecording information is obtained.

Next, in step S54, disk recording information adapted to the diskrecording information acquisition command (a command of “Read DiskInformation” or “Read Track Information”) is returned to the hostcomputer 21 to notify the user of the data recording information.Thereby, the user can specify a desired erasing area.

Next, in step S55, it is checked whether the data erasing apparatus 22receives an erasing command which is issued from the host computer 21.When the apparatus 22 receives this command, the process goes to stepS56.

Next, in step S56, it is determined whether data have already written inthe loaded optical disk 111 or not. When the optical disk 111 isdetermined as an already-recorded CD-R disk, the process goes to stepS57. Otherwise, the process goes to step S58.

In step S57, the erasing area S53 specified by the erasing command iscompared with the recording area obtained in step S53, and only therecording area corresponding to the specified erasing area is irradiatedwith a laser beam having a recording power equal to or higher than thatat recording to overwrite the recording area, whereby data recorded inthe specified area are erased. In this way, the user can erase only adesired area.

When an optical disk other than the already-recorded CD-R disk isloaded, the erasing command becomes invalid and, in step S58, an errorsignal indicating that the loaded disk is an inerasable disk is returnedto the host computer 21. Since there is no need to execute data erasingwhen no data are recorded on the optical disk 111, needless operation isavoided, resulting in reduced cost.

As described above, in the optical disk data erasing apparatus accordingto the first embodiment, it is judged whether the loaded optical disk111 is a write-once disk (CD-R disk) or not, and when it is a write-oncedisk, overwriting is carried out by irradiating the optical disk 111with a laser beam having a recording power equal to or higher than thatat recording, thereby erasing data recorded on the optical disk 111.Therefore, an optical disk data erasing apparatus which is able tocompletely erase data recorded on an optical disk is realized easily, atlow cost, without having to use a special apparatus and withoutgenerating substances detrimental to environment, whereby leakage ofsecret information can be prevented when the disk is discarded.

Further, when the host computer 21 issues a disk recording informationacquisition instruction, disk recording information relating to adata-recorded area or a data-unrecorded area of the optical disk 111 isobtained. Therefore, data erasing can be performed on only thedata-recorded area, while the data-unrecorded area, which needs not beerased, is outside the target of data erasing, whereby the time requiredfor data erasing is reduced.

Embodiment 2

Hereinafter, an optical disk data erasing apparatus according to asecond embodiment of the present invention will be described. FIG. 1 isa block illustrating the construction of an optical disk data erasingapparatus according to the second embodiment. FIG. 2 is a block diagramillustrating the construction of a data erasing system according to thesecond embodiment. FIG. 4 is a diagram illustrating an example of a diskformat according to the second embodiment. Since FIGS. 1, 2, and 4 havealready been described with respect to the first embodiment, repeateddescription is not necessary.

The optical disk data erasing apparatus 22 according to the secondembodiment is provided with a judgement means for making a judgement asto whether the loaded optical disk 111 is a write-once optical disk(CD-R disk) or not; a disk recording information acquisition means forobtaining information relating to a data-recorded area or adata-unrecorded area (blank area) of the CD-R disk 111, on the basis ofa disk recording information acquisition instruction from the hostcomputer 21; a notification means for notifying the user of the diskrecording information through the host computer 21; an erasing areadetection means for detecting, when an instruction that specifies anarea from which data are to be erased (hereinafter referred to as “anerasing area”) is issued by the user through the host computer 21 on thebasis of the disk recording information, an area corresponding to thespecified erasing area; a determination means for determining whetherdata are recorded on the CD-R disk 111 or not, on the basis of the diskrecording information; and a setting means with which the user sets,through the host computer 21, whether or not the interface bus is to beoccupied during execution of data erasing.

Next, an optical disk data erasing method according to this secondembodiment will be described with reference to FIG. 6.

When the optical disk 111 is loaded on the data erasing apparatus 22,initially, the CPU 101 controls the rotation control circuit 109 to spinup the motor 110 in step S61. Then, the loaded optical disk 111 isirradiated with a laser beam to read data recorded on the optical disk111, and it is judged whether the optical disk 111 is a CD-R disk ornot, on the basis of WOBBLE information which is obtained through theEFM WOBBLE signal processing circuit 105. When it is a CD-R disk, theprocess goes to step S62.

In step S62, it is checked whether or not the data erasing apparatus 22receives a disk recording information acquisition command (a command of“Read Disk Information” or “Read Track Information”) which is outputtedfrom the host computer 21. When the apparatus 22 receives the command,the process goes to step S63.

In step S63, the disk recording information of the CD-R disk 111 isobtained. To be specific, the disk recording information is obtained asfollows. Initially, the outline of the disk recording state is graspedon the basis of the information about the start time and end time of thealready-recorded track and reserved track, which information is recordedin the PMA 42 at the inner circumference of the disk 111, and the TOCinformation which is recorded in the read-in area 43 of each session,and a break between pits of the data-recorded area and thedata-unrecorded area is actually detected to recognize the details ofthe disk recording state, thereby obtaining the disk recordinginformation.

Next, in step S64, the disk recording information adapted to the diskrecording information acquisition command (a command of “Read DiskInformation” or “Read Track Information”) is returned to the hostcomputer 21 to notify the user of the data recording information.Thereby, the user can specify a desired erasing area.

Next, in step S65, it is checked whether or not the data erasingapparatus 22 receives an erasing command which is outputted from thehost computer 21. When the apparatus 22 receives the command, theprocess goes to step S66.

Next, in step S66, it is checked whether data have already been writtenin the loaded optical disk 111 or not. When the optical disk 111 isjudged as an already-recorded CD-R disk, the process goes to step S67.Otherwise, the process goes to step S6F.

In step S6F, when the disk 111 is not an already-recorded CD-R disk, theerasing command becomes invalid, and an error signal indicating that theoptical disk 111 is an inerasable disk is returned to the host computer21. Since there is no need to execute data erasing when no data arerecorded on the optical disk 111, needless operation is avoided,resulting in reduced cost.

In step S67, it is checked whether the disk erasing command indicates“Immediate” designating that the interface bus is to be occupied or “NonImmediate” designating that the interface bus is not to be occupied. Inthe case where the “Immediate” designating command is received, theprocess goes to step S68. In the case where the “Non Immediate”designating command is received, the process goes to step S6D.

In step S68, a response to the command is immediately returned to thehost computer 21 to release the interface bus. Thereafter, in step S69,erasing of data in the specified area is started. In step S6A, it ischecked whether or not the data erasing apparatus 22 receives a drivingstate monitor command such as “Test Unit Ready” or the like. When theapparatus 22 receives the command, the process goes to step S6B. In stepS6B, it is notified to the host computer 21 that the data erasing stateof the data erasing apparatus 22 is any of the following states: thestate where data erasing is being executed, the state where data erasinghas normally ended, and the state where the data erasing has abnormallyended. Then, as shown in step S6C, until the host computer 21 isnotified by the data erasing apparatus 22 that the data erasing hasnormally ended or that it has abnormally ended, the host computer 21continues to periodically output a driving state monitor command in stepS6A. In this way, since the host computer 21 periodically checks thedata erasing state to confirm the completion of data erasing, the hostcomputer 21 can execute another processing while the data erasingapparatus 22 is executing data erasing.

In the case where the “Non Immediate” designating command is received,the process goes to step S6D wherein the data erasing apparatus 22executes erasing of the specified area. Thereafter, in step S6E, thedata erasing apparatus 22 outputs a response to the command, whichindicates that the data erasing has normally ended or abnormally ended,to the host computer 21. Thereby, the host computer 21 can speedilydetect the completion of data erasing.

In both of steps S69 and S6D, the erasing area specified by the erasingcommand is compared with the recording area obtained in step S63, andonly the recording area corresponding to the specified erasing area isoverwritten by irradiating the area with a laser beam having a recordingpower equal to or higher than that at recording, thereby erasing therecorded data.

In the optical disk data erasing apparatus according to the secondembodiment, it is judged whether the loaded optical disk 111 is awrite-once optical disk or not, and when the disk 111 is a write-onceoptical disk, overwriting of the optical disk 111 is carried out byirradiating the optical disk 111 with a laser beam having a recordingpower equal to or higher than that at recording, on the basis of acommand from the host computer 21, thereby erasing the recorded data.Therefore, an optical disk data erasing apparatus, which is able tocompletely erase data recorded on an optical disk, can be realizedeasily, at low cost, without having to use a special apparatus andwithout generating substances detrimental to environment, wherebyleakage of secret information can be prevented when the optical disk isdiscarded.

Furthermore, the data erasing apparatus 22 obtains disk recordinginformation relating to a data-recorded area or a data-unrecorded areaof the optical disk 111 when the host computer 21 outputs a diskrecording information acquisition command. Therefore, the data erasingapparatus 22 can perform data erasing on only the data-recorded areawithout performing data erasing on the data-unrecorded area which needsnot be erased, whereby the time required for data erasing is reduced.

Furthermore, the interface bus is to be occupied or not during executionof data erasing is set by the user through the host computer 21.Therefore, when it is set that the interface bus is not to be occupied,the host computer 21 can perform another processing while the dataerasing apparatus 22 is executing data erasing. Further, when theinterface bus is to be occupied, the host computer 21 can speedilydetect the end of data erasing by the data erasing apparatus 22.

Embodiment 3

Hereinafter, an optical disk data erasing apparatus according to a thirdembodiment of the present invention will be described. FIG. 1 is a blockdiagram illustrating the construction of an optical disk data erasingapparatus according to the third embodiment. Since FIG. 1 has alreadybeen described with respect to the first embodiment, repeateddescription is not necessary.

The optical disk data erasing apparatus 22 according to the thirdembodiment is provided with a first jumper switch setting means forsetting ON/OFF of a first jumper switch 32; a second jumper switchsetting means for setting ON/OFF of a second jumper switch 33; a settingdistinguishing means for distinguishing whether the first jumper switch32 and the second jumper switch 33 are ON or OFF; a judgement means forjudging whether the loaded optical disk 111 is a CD-R disk or not; anerasing means for erasing recorded data, on the basis of the setting ofthe first and second jumper switches 32 and 33; an ejection means forautomatically ejecting the disk 111 after data erasing; a disk recordinginformation acquisition means for acquiring information relating to adata-recorded area or a data-unrecorded area of the CD-R disk 111; and adetermination means for determining whether data are recorded on theCD-R disk 111 or not, on the basis of the disk recording informationobtained by the disk recording information acquisition means.

FIG. 3(a) shows a front view of the optical disk erasing apparatus 22(drive), and FIG. 3(b) shows a rear view of the drive. In these Figures,31 denotes an ejection button, 32 denotes a first jumper switch, 33denotes a second jumper switch, 34 denotes an LED (Light EmittingDiode), and 35 denotes an interface connector.

The first jumper switch 32 indicates that the erasing operation is to beexecuted when it is ON, and the second jumper switch 33 indicates thatthe entire disk surface is to be erased when it is ON and that therecorded area in final session is to be erased when it is OFF.

The optical disk data erasing apparatus 22 according to the thirdembodiment automatically ejects the disk 111 and turns the LED 34 onwhen the first jumper switch 32 is OFF, or when it is recognized thatthe data erasing has not normally ended, or when it is determined thatdata are not recorded on the CD-R disk.

While in this third embodiment the LED 34 is turned on as a displaymeans for indicating that data erasing is not carried out, the presentinvention is not restricted thereto, and other methods may be employed.

FIG. 4 shows an example of a disk format according to the thirdembodiment. Since FIG. 4 has already been described with respect to thefirst embodiment, repeated description is not necessary.

In FIG. 4, when the second jumper switch 33 is ON, overwriting isexecuted on an overwriting target area 1. Further, when the secondjumper switch 33 is OFF, overwriting is executed on an overwritingtarget area 2.

Hereinafter, an optical disk data erasing method according to the thirdembodiment will be described with reference to FIG. 7.

Initially, in step S71, the optical disk data erasing apparatus 22checks the states of the first and second jumper switches 32 and 33 onthe rear surface of the drive when the power is turned on.

In step S72, the ejection button 31 is pushed down, whereby the CPU 101operates the rotation control circuit 109 so as to spin up the motor 110when the optical disk 111 is loaded on the data erasing apparatus 22.Then, the loaded optical disk 111 is irradiated with a laser beam toread data recorded on the optical disk 111, and WOBBLE information isextracted from the optical disk 111 by the EFM WOBBLE signal processingcircuit 105. Then, it is judged whether the optical disk 111 is a CD-Rdisk or not on the basis of the extracted WOBBLE information, followedby step S73.

In step S73, when it is confirmed in step S71 that the jumper switch 32is ON (designation of erasing operation) and it is confirmed in step S72that the optical disk 111 is a CD-R disk, the process goes to step S74.Otherwise, the process goes to step S7B.

In step S74, the disk recording information of the CD-R disk 111 isobtained.

To be specific, the disk recording information is obtained as follows.That is, an outline of the disk recording state is grasped on the basisof the information about the start time and end time of analready-recorded track and a reserved track, which is recorded in thePMA 42 at the inner circumference of the disk 111, as well as the TOCinformation which is recorded in the read-in area 43 of each session,and a break of pits between the recorded area and the unrecorded area isdetected actually to recognize the details of the disk recording state,thereby obtaining the disk recording information. Therefore, the dataerasing apparatus 22 can perform data erasing on only the data-recordedarea without performing data erasing on the data-unrecorded area whichneeds not be erased, whereby the time required for data erasing isreduced.

In step S75, it is checked whether data have already been recorded onthe optical disk 111 or not. When data have already been recorded on thedisk 111, the process goes to step S76. Otherwise, the process goes tostep S7B.

In step S76, the setting of the second jumper switch 33 is checked. Whenthe second jumper switch 33 is set in the ON state, the process goes tostep S77, wherein the entire surface of the disk is subjected to dataerasing. When the second jumper switch 33 is in the OFF state, theprocess goes to step S78, wherein the data-recorded area in the finalsession is subjected to data erasing.

In both of steps S77 and S78, the erasing area specified by the erasingcommand is compared with the recording area obtained in step S74, andonly the recording area corresponding to the specified erasing area isoverwritten by irradiating the area with a laser beam having a recordingpower equal to or higher than that at recording, thereby erasing therecorded data.

In step S79, it is checked whether the data erasing executed in stepsS77 and S78 has normally ended or not. When the data erasing hasnormally ended, the data-erased optical disk 111 is automaticallyejected in step S7A.

When the disk 111 loaded in step S75 is other than the already-recordedCD-R disk or when the data erasing process has abnormally ended in stepsS77 and 78, the disk is automatically ejected in step S7A, and the LED34 is turned on to notify the user that the data erasing ends infailure.

When the optical disk data erasing apparatus 22 is connected to an autochanger, the effectiveness of the data erasing apparatus 22 relating toautomation of erasing work and cost-down is enhanced.

In the optical disk data erasing apparatus according to the thirdembodiment, after ON/OFF of the first and second jumper switches 32 and33 are set and the loaded optical disk is judged as a CD-R disk,overwriting of the optical disk 111 is executed by irradiating theoptical disk with a laser beam having a recording power equal to orhigher than that at recording, according to the setting of the first andsecond jumper switches 32 and 33, thereby erasing the recorded data.After the data erasing, the optical disk 111 is automatically ejected.Therefore, erasing of data on the optical disk can be executed by theoptical disk data erasing apparatus 22 alone, according to the externaloperation, without using the host computer, and the erasing process canbe automated. As the result, an optical disk data erasing apparatuswhich is able to completely erase recorded data easily, at low cost,whereby leakage of secret information is prevented when the optical diskis discarded.

Further, when the loaded optical disk 111 is not a CD-R disk, or whenthe first jumper switch 32 is OFF and the erasing operation is not set,or when the data erasing of the optical disk 111 has not normally ended,the loaded optical disk 111 is automatically ejected and the LED 34 isturned on. Therefore, the user can know that the data erasing ends infailure, whereby the user is prevented from recognizing that the dataerasing has normally ended, and from discarding the optical disk onwhich the recorded data to be erased is not erased.

1-24. (canceled)
 25. An optical disk data erasing apparatus which is anoptical disk recording apparatus for writing or reading data in/from arecordable optical disk by irradiating the optical disk with a laserbeam, said optical disk recording apparatus being connected to a hostcomputer through an interface bus, said optical disk data erasingapparatus comprising: a judgement means for judging as to whether aloaded optical disk is a write-once optical disk or not; an instructionrecognition means for recognizing an instruction from the host computer;an erasing means for executing a data erasing process on the basis ofthe instruction; a setting means with which the user sets, through thehost computer, whether the interface bus is to be occupied or not duringexecution of the data erasing process; and a monitor means formonitoring the data erasing state on the basis of a state monitoringinstruction which is periodically issued from the host computer, when itis set that the interface bus is not to be occupied, wherein saiderasing means overwrites the optical disk which is judged as awrite-once optical disk by the judgement means, by irradiating theoptical disk with a laser beam having the same recording power as thatat recording, thereby erasing data recorded on the optical disk, andwherein said host computer is able to execute another process duringexecution of the data erasing process, when it is set that the interfacebus is not to be occupied.
 26. An optical disk data erasing apparatuswhich is an optical disk recording apparatus for writing or reading datain/from a recordable optical disk by irradiating the optical disk with alaser beam, said optical disk recording apparatus being connected to ahost computer through an interface bus, said optical disk data erasingapparatus comprising: a judgement means for making a judgement as towhether a loaded optical disk is a write-once optical disk or not; aninstruction recognition means for recognizing an instruction from thehost computer; an erasing means for executing a data erasing process onthe basis of the instruction; a setting means with which the user sets,through the host computer, whether the interface bus is to be occupiedor not during execution of the data erasing process; and a monitor meansfor monitoring the data erasing state on the basis of a state monitoringinstruction which is periodically issued from the host computer, when itis set that the interface bus is not to be occupied, wherein saiderasing means overwrites the optical disk which is judged as awrite-once optical disk by the judgement means, by irradiating theoptical disk with a laser beam having a recording power higher than thatat recording, thereby erasing data recorded on the optical disk, andwherein said host computer is able to execute another process duringexecution of the data erasing process, when it is set that the interfacebus is not to be occupied.
 27. An optical disk data erasing apparatuswhich is an optical disk recording apparatus for writing or reading datain/from a recordable optical disk by irradiating the optical disk with alaser beam, said optical disk data erasing apparatus comprising: a firstjumper switch setting means for setting ON/OFF of a first jumper switch;a setting identification means for identifying the setting of the firstjumper switch; a judgement means for making a judgement as to whether aloaded optical disk is a write-once optical disk or not; an erasingmeans for overwriting the write-once optical disk by irradiating theoptical disk with a laser beam having the same recording power as thatat recording, according to the setting of the first jumper switch,thereby erasing data recorded on the optical disk; and an ejection meansfor automatically ejecting the optical disk after the data erasingprocess; wherein, when the first jumper switch is turned ON, saiderasing means starts the data erasing operation; and when the firstjumper switch is OFF or when the judgement means judges that the loadedoptical disk is not a write-once optical disk, said ejection meansautomatically ejects the optical disk, and a display means displays thatthe data erasing process is not to be executed on the optical disk. 28.An optical disk data erasing apparatus as defined in claim 27 furthercomprising: a checking means for checking whether the data erasingprocess has normally ended or not; wherein, when the data erasingprocess for the write-once optical disk has not normally ended, saidejection means automatically ejects the optical disk, and said displaymeans displays that the data erasing process is not to be executed onthe optical disk.
 29. An optical disk data erasing apparatus as definedin claim 28 further comprising: a second jumper switch setting means forsetting ON/OFF of a second jumper switch; wherein said settingidentification means identifies the setting of the second jumper switch;when it is identified that the second jumper switch is ON, said erasingmeans executes the data erasing process over the entire surface of theoptical disk; and when it is identified that the second jumper switch isOFF, said erasing means executes the data erasing process on a finalsession.
 30. An optical disk data erasing apparatus as defined in claim27 further comprising: a disk recording information acquisition meansfor acquiring information relating to a data-recorded area or adata-unrecorded area of the write-once optical disk; wherein saiderasing means erases recorded data from the data-recorded area.
 31. Anoptical disk data erasing apparatus as defined in claim 30 furthercomprising: a determination means for determining whether data arerecorded on the write-once optical disk or not, on the basis of the diskrecording information obtained by the disk recording informationacquisition means; wherein, when data are recorded on the write-onceoptical disk, said erasing means executes the recorded-data erasingprocess; and when no data are recorded on the write-once optical disk,said ejection means automatically ejects the optical disk, and thedisplay means displays that the data erasing process is not to beexecuted on the optical disk.
 32. An optical disk data erasing apparatuswhich is an optical disk recording apparatus for writing or reading datain/from a recordable optical disk by irradiating the optical disk with alaser beam, said optical disk data erasing apparatus comprising: a firstjumper switch setting means for setting ON/OFF of a first jumper switch;a setting identification means for identifying the setting of the firstjumper switch; a judgement means for making a judgement as to whether aloaded optical disk is a write-once optical disk or not; an erasingmeans for overwriting the write-once optical disk by irradiating theoptical disk with a laser beam having a recording power higher than thatat recording, according to the setting of the first jumper switch,thereby erasing the data recorded on the optical disk; and an ejectionmeans for automatically ejecting the optical disk after the data erasingprocess; wherein, when the first jumper switch is turned ON, saiderasing means starts the data erasing operation; and when the firstjumper switch is OFF or when the judgement means judges that the loadedoptical disk is not a write-once optical disk, said ejection meansautomatically ejects the optical disk, and display means displays thatthe data erasing process is not to be executed on the optical disk. 33.An optical disk data erasing apparatus as defined in claim 32 furthercomprising: a checking means for checking whether the data erasingprocess has normally ended or not; wherein, when the data erasingprocess for the write-once optical disk has not normally ended, saidejection means automatically ejects the optical disk, and said displaymeans displays that the data erasing process is not to be executed onthe optical disk.
 34. An optical disk data erasing apparatus as definedin claim 33 further comprising: a second jumper switch setting means forsetting ON/OFF of a second jumper switch; wherein said settingidentification means identifies the setting of the second jumper switch;when it is identified that the second jumper switch is ON, said erasingmeans executes the data erasing process over the entire surface of theoptical disk; and when it is identified that the second jumper switch isOFF, said erasing means executes the data erasing process on a finalsession.
 35. An optical disk data erasing apparatus as defined in claim32 further comprising: a disk recording information acquisition meansfor acquiring information relating to a data-recorded area or adata-unrecorded area of the write-once optical disk; wherein saiderasing means erases recorded data from the data-recorded area.
 36. Anoptical disk data erasing apparatus as defined in claim 35 furthercomprising: a determination means for determining whether data arerecorded on the write-once optical disk or not, on the basis of the diskrecording information obtained by the disk recording informationacquisition means; wherein, when data are recorded on the write-onceoptical disk, said erasing means executes the recorded-data erasingprocess; and when no data are recorded on the write-once optical disk,said ejection means automatically ejects the optical disk, and thedisplay means displays that the data erasing process is not to beexecuted on the optical disk.